1. Field of the Invention
The invention relates to an overdriving technique. Particularly, the invention relates to an overdriving value generating method.
2. Description of Related Art
Along with development of modern video technology, liquid crystal displays (LCDs) have been widely used as displays of consumer electronic products. However, since a LCD panel of the LCD does not emit light itself, a backlight module is disposed under the LCD panel to provide a light source required by the LCD panel, so as to achieve a display effect. Most of the current LCDs apply a hold type backlight module to provide the required light source with a fixed light amplitude. Therefore, when the LCD displays a static image, an image flickering problem is not occurred, and the user' eye may have a comfortable feeling when watching the static image.
However, when the LCD displays dynamic images, since the human eye operates in an integrating mode, the hold type backlight may cause obscure of the image outline or image sticking and ghost image phenomenon when the dynamic image is displayed, which is the so-called motion blur. In order to resolve the above problem, the conventional technique applies an overdriving (OD) technique to shorten a pixel response time.
Presently, when the overdriving technique is used, a look-up table is required to be established to record overdriving values corresponding to different gray values, and a signal of the gray value to be output is modified according to the look-up table, so as to shorten the response time of the liquid crystal. Moreover, the size of the look-up table is the square of the resolution of the gray value signal, namely, the look-up table establishes the overdriving value corresponding to each gray value with reference of a previous gray value and a current gray value. In this way, the overdriving values can correctly correspond to the gray levels. However, considering hardware cost, the size of the look-up table is reduced, so that the number of the recorded previous gray values and the gray values are reduced. Moreover, the previous gray values and the gray values that are not recorded on the look-up table can only be obtained by referring to the closed previous gray values and the closed gray values, which makes the output overdriving values are not accurate.